Match add network button width to master switch and tint it.

It's now tinted in colorAccent.

Created a new default 80dp minWidth for TwoTargetPreferences.

Fixes: 129007966
Test: visual inspection
Change-Id: Ie751fe685d25373c3aac001e6e0daee8e18b9314

res/layout/preference_widget_add.xml

@@ -21,10 +21,12 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:layout_gravity="center"
+    android:minWidth="@dimen/two_target_min_width"
     android:paddingStart="?android:attr/listPreferredItemPaddingEnd"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
     android:background="?android:attr/selectableItemBackground"
     android:scaleType="center"
     android:src="@drawable/ic_add_24dp"
+    android:tint="?android:attr/colorAccent"
     android:contentDescription="@string/add" />
 

res/layout/preference_widget_master_switch.xml

@@ -20,6 +20,7 @@
     android:id="@+id/switchWidget"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:minWidth="@dimen/two_target_min_width"
     android:gravity="center_vertical"
     android:paddingStart="?android:attr/listPreferredItemPaddingEnd"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"

res/values/dimens.xml

@@ -393,4 +393,6 @@
 
     <!-- Elevation of bluetooth icon -->
     <dimen name="bt_icon_elevation">4dp</dimen>
+
+    <dimen name="two_target_min_width">80dp</dimen>
 </resources>